The invention is directed to a deburring cutter according to the preamble of claim 1.
A first embodiment of a cutter, known as a DEFA cutter, by the same applicant has a straight, vertical cutting edge. A control surface is disposed on the front free end of the cutting edge. The control surface is radially inwardly inclined, does not cut, and functions only as a control surface for the vertically oriented cutting edge. The inclined control surface transitions into a horizontal front end.
With the DEFA cutter, the chamfer diameter of the drilled hole to be deburred can advantageously be set very accurately and does not change during the deburring process.
This may be due to the fact that the vertical cutting edge performs an excellent cutting action as a result of the forced control by the inclined control edge located subsequent to the vertical cutting edge.
If the inclined control edge were omitted, the DEFA cutter would operate only as a countersink tool, without being centered in the drilled hole.
In another embodiment of a cutter, the so-called GHS cutter by the same applicant, a different cutting geometry was used which essentially consists of a radially inwardly inclined cutting edge that transitions on its free front end directly into an ineffectual, non-cutting end face. Unlike the DEFA cutter, this embodiment does not include the so-called control edge.
Advantageously, the GHS cutter is capable of achieving a large forward feed with excellent angular accuracy of the chamfer to be deburred. Only a small secondary edge was produced.
In this disadvantageous arrangement, the control edge has been omitted, which could cause a variable, uneven chamfer. When the cutter becomes dull, the exact chamfer diameter can no longer be guaranteed.
It is therefore an object of the invention to provide a deburring cutter for deburring edges of a drilled hole in workpieces of the aforedescribed type, which can effectively remove large burrs from the edge of the drilled hole, while accurately maintaining the chamfer or countersink geometry of the edges of the drilled hole and, in particular, of the countersink angle more or less independent of the wear of the cutting edges, whereby the cutter can be precisely controlled by a control surface.
According to the invention, a novel cutter is provided, wherein the at least one cutting section has a first cutting edge directly or indirectly followed by a second cutting edge, with a non-cutting free edge arranged after the second cutting edge indirectly via a transition, with the free edge being recessed radially toward the rotation axis with respect to the second cutting edge. The first cutting edge encloses with the rotation axis an angle in the range of approximately 45° to 120°, and the second cutting edge encloses, on one hand, with the rotation axis an angle in the range of approximately 0° to 90° and, on the other hand, with the first cutting edge an outside angle greater than 180°. A control edge is located behind the free edge, as viewed in a direction opposite the rotation direction, which has at least partially the same radial distance with respect to the rotation axis as the second cutting edge. More particularly, the free edge encloses with the second cutting edge an angle between approximately 90° and 270°. The invention relates to clockwise and counter-clockwise rotating cutters.